summaryrefslogtreecommitdiff
path: root/include/linux/serial_core.h
diff options
context:
space:
mode:
authorLukas Wunner <lukas@wunner.de>2020-05-18 17:45:02 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-05-29 13:42:54 +0300
commitd58a2df3d8877b91ecbfb936a15da364251a228f (patch)
tree3d4552397dddb3809888ba9094415ae7eac46239 /include/linux/serial_core.h
parentf40a6be4a4e4985aef5365007e2459d757f26bdd (diff)
downloadlinux-d58a2df3d8877b91ecbfb936a15da364251a228f.tar.xz
serial: 8250: Support rs485 bus termination GPIO
Commit e8759ad17d41 ("serial: uapi: Add support for bus termination") introduced the ability to enable rs485 bus termination from user space. So far the feature is only used by a single driver, 8250_exar.c, using a hardcoded GPIO pin specific to Siemens IOT2040 products. Provide for a more generic solution by allowing specification of an rs485 bus termination GPIO pin in the device tree: Amend the serial core to retrieve the GPIO from the device tree (or ACPI table) and amend the default ->rs485_config() callback for 8250 drivers to change the GPIO on request from user space. Perhaps 8250_exar.c can be converted to the generic approach in a follow-up patch. Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Link: https://lore.kernel.org/r/94c6c800d1ca9fa04766dd1d43a8272c5ad4bedd.1589811297.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/serial_core.h')
-rw-r--r--include/linux/serial_core.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index b649a2b894e7..9fd550e7946a 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -10,6 +10,7 @@
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <linux/console.h>
+#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/circ_buf.h>
#include <linux/spinlock.h>
@@ -251,6 +252,7 @@ struct uart_port {
struct attribute_group *attr_group; /* port specific attributes */
const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
struct serial_rs485 rs485;
+ struct gpio_desc *rs485_term_gpio; /* enable RS485 bus termination */
struct serial_iso7816 iso7816;
void *private_data; /* generic platform data pointer */
};